Comment 3 for bug 1651273

I haven't tried recently, but the cache still exists (in aodh-evaluator):

http://git.openstack.org/cgit/openstack/aodh/tree/aodh/evaluator/event.py#n185

and it is only cleared after self.conf.event_alarm_cache_ttl seconds. Given that this is the case, there can't not be a case where the cache is stale.

Note that to reproduce you must populate the cache, so e.g. generate an event for a project, then add an alarm, then generate another event <60s later. The second event won't result in an alarm even if it matches.